1. Field of the Invention
The invention relates to taps and refers more specifically to a double ended tap, both ends of which may be used for the purpose of cutting threads, and a tool holder for holding the tap by either end thereof and imparting torque thereto to effect cutting therewith.
2. Description of the Prior Art
In the past, taps have been single ended tools including threads on one end and a shank on the other. With such structure, the shanks are especially designed to be held in tool holders which impart rotation to the taps for effecting cutting of threads with the threaded end of the tap.
Such taps having particular configurations at the opposite ends for cutting threads and to promote holding of the tap by a tool holder while torque is imparted to the tap are wasteful of material and machining time in the manufacture thereof and are therefore expensive.